Merge "Postpone window_state_changed events until the window is added" into...

Merge "Postpone window_state_changed events until the window is added" into tm-dev am: 857459ff am: 4db5aded am: 7b5e81f2 am: 6fefffe4

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/17741153



Change-Id: Icedf6ee037bca3e851b347b957cfdcbd9f452c19
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>